A three dimensional printing apparatus for photocured molding comes out at present, in which the photocured molding is the technology of curing a photocured material for molding by the irradiation from a beam. However, some conventional three-dimensional printing apparatuses are unable to change the photocured material during the printing process, so that the conventional three-dimensional printing apparatus can only manufacture an object composed of one kind of material. Other conventional three-dimensional printing apparatuses which can change the photocured material during the printing process have complicated-structures and high cost.